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Showing papers on "Open-channel flow published in 1988"


Journal ArticleDOI
TL;DR: In this article, the Reynolds stresses and the dissipation rate of the turbulence kinetic energy are computed using direct simulation data of a turbulent channel flow using a closed-loop model, where the budget data reveal that all the terms in the budget become important close to the wall.
Abstract: The budgets for the Reynolds stresses and for the dissipation rate of the turbulence kinetic energy are computed using direct simulation data of a turbulent channel flow. The budget data reveal that all the terms in the budget become important close to the wall. For inhomogeneous pressure boundary conditions, the pressure-strain term is split into a return term, a rapid term, and a Stokes term. The Stokes term is important close to the wall. The rapid and return terms play different roles depending on the component of the term. A split of the velocity pressure-gradient term into a redistributive term and a diffusion term is proposed, which should be simpler to model. The budget data is used to test existing closure models for the pressure-strain term, the dissipation rate, and the transport rate. In general, further work is needed to improve the models.

788 citations


Journal ArticleDOI
TL;DR: In this paper, the problem of low Reynolds number wetting liquid flow in a noncircular capillary occupied predominantly by a nonwetting gas phase is separated into individual corner flow problems and solved numerically.

349 citations


Journal ArticleDOI
TL;DR: In this paper, the fluctuating wall-shear stress was measured with various types of hotwire and hot-film sensors in turbulent boundary layer and channel flows, and the rms level of the streamwise wall shear stress fluctuations was found to be 40% of the mean value, which was substantiated by measurements of streamwise velocity fluctuations in the viscous sublayer.
Abstract: The fluctuating wall‐shear stress was measured with various types of hot‐wire and hot‐film sensors in turbulent boundary‐layer and channel flows. The rms level of the streamwise wall‐shear stress fluctuations was found to be 40% of the mean value, which was substantiated by measurements of the streamwise velocity fluctuations in the viscous sublayer. Heat transfer to the fluid via the probe substrate was found to give significant differences between the static and dynamic response for standard flush‐mounted hot‐film probes with air or oil as the flow medium, whereas measurements in water were shown to be essentially unaffected by this problem.

333 citations


Journal ArticleDOI
TL;DR: In this article, a mathematical model for calculating suspended sediment transport in unidirectional channel flow under general, non-equilibrium conditions is presented, which consists of a flexible hydrodynamic component for calculating the flow field and the turbulence characteristics and a scalar transport model.
Abstract: A mathematical model is presented for calculating suspended sediment transport in unidirectional channel flow under general, non-equilibrium conditions. The model consists of a flexible hydrodynamic component for calculating the flow field and the turbulence characteristics and a scalar transport model. The former employs the \Ik\N-e turbulence model and provides, as input to the latter, the distribution of velocity and eddy diffusivity as well as the friction velocity. The settling process is simulated with an empirical settling velocity appearing in the particle concentration equation. As a boundary condition for this equation, the net flux of sediment to and from the bed is prescribed with a new model which covers both fixed-bed and erodable-bed situations. The net flux is expressed as the difference between deposition to and entrainment from the bed and, while the deposition rate is known from the local concentration and settling velocity, the entrainment is assumed to occur at the same rate as it does under equilibrium conditions, provided sufficient sediment material is available. With the aid of a finite volume procedure, the combined hydrodynamic sediment transport model is applied to a variety of flume experiments involving zero net flux, net-deposition, and net-entrainment situations. The predicted development of the vertical concentration profiles is compared with the measurements and generally good agreement is obtained.

198 citations


Journal ArticleDOI
TL;DR: In this article, the transverse development of the turbulent mixing layers in an open channel flow of shallow water depth was investigated experimentally to study the confinement and bed-friction effects.
Abstract: The transverse development of the turbulent mixing layers in an open channel flow of shallow water depth was investigated experimentally to study the confinement and bed-friction effects. Mean and r.m.s. velocity profiles were obtained, using a hot-film anemometer, at a number of cross sections downstream of a splitter plate between two streams of different velocities. In the confinement between the free surface and the channel bed, the transverse spreading rate of the shallow mixing layer was initially twice as large as the nominal rate for the free mixing layer. The spreading rate reduces with distance from the splitter plate under the stabilizing influence of bed-friction, and diminishes to zero in the far field region when the bed-friction number exceeds a critical value of about 0.09.

173 citations


Proceedings ArticleDOI
01 Jan 1988
TL;DR: In this paper, the Navier-Stokes equations are solved in a time-accurate manner in using the method of pseudocompressibility, where subiterations in pseudotime are required to satisfy the continuity equation at each time step.
Abstract: The two-dimensional incompressible Navier-Stokes equations are solved in a time-accurate manner in using the method of pseudocompressibility. Using this method, subiterations in pseudotime are required to satisfy the continuity equation at each time step. An upwind differencing scheme based on flux-difference splitting is used to compute the convective terms. The upwind differencing is biased based on the sign of the local eigenvalue of the Jacobian matrix. Third-order or fifth-order spatial accuracy is maintained throughout the interior grid points. The equations are solved using an implicit line-relaxation scheme. This solution scheme is stable and is capable of running at large time steps in pseudotime, leading to fast convergence for each physical time step. A variety of computed results are presented to validate the present scheme. Results for the flow over an oscillating plate are compared with the exact analytic solution, good agreement is seen. Excellent comparison is obtained between the computed solution and the analytical results for inviscid channel flow with an oscillating back pressure. Flow solutions over a circular cylinder with vortex shedding are also presented. Finally, the flow past an airfoil at -90 deg angle-of-attack is also computed.

142 citations


Patent
20 Apr 1988
TL;DR: In this article, a sheath flow type flow-cell device for plow-cytometer which comprises a first inlet for sheath fluid, a flow passage communicated with the first flow inlet and contracted toward downstream, the flow passage having a substantially rectangular cross section, a straight capillary flow passage connected to the flow downstream thereof, a second inlet was provided at a terminal end of the straight flow passage, and flow regulating means for regulating the flow of the sheath fluids in the straight caula flow passage to be a laminar flow having a gradient
Abstract: A sheath flow type flow-cell device for plow-cytometer which comprises a first inlet for sheath fluid, a flow passage communicated with the first inlet and contracted toward downstream, the flow passage having a substantially rectangular cross section, a straight capillary flow passage connected to the flow passage downstream thereof, the capillary flow passage having a substantially rectangular cross section, a second inlet for sample fluid, a nozzle communicating with the second inlet and opened within the flow passage in the same direction as the flow direction of the straight capillary flow passage, a discharge port provided at a terminal end of the straight capillary flow passage, and flow regulating means for regulating the flow of the sheath fluid in the straight capillary flow passage to be a laminar flow having a gradient of flow velocity.

139 citations


Journal ArticleDOI
TL;DR: In this paper, a two-component laser-Doppler velocimeter was used to obtain simultaneous measurements of the velocity components parallel and normal to the wall in two well-mixed low-concentration drag-reducing channel flows and one turbulent channel flow.
Abstract: A two-component laser-Doppler velocimeter was used to obtain simultaneous measurements of the velocity components parallel and normal to the wall in two fully developed well-mixed low-concentration drag-reducing channel flows and one turbulent channel flow. For the drag-reducing flows, the average time between bursts was found to increase. Although the basic structure of the fundamental momentum transport event is shown to be the same in these drag-reducing flows, the lower-threshold Reynolds-stress-producing motions were found to be damped, while the higher-threshold motions were not. It is suggested that some strong turbulent motions are needed to maintain extended polymer molecules, which produce a solution with properties that can damp lower threshold turbulence and thereby reduce viscous drag.

133 citations


Journal ArticleDOI
TL;DR: In this paper, it is shown that the addition of small cylinders to a plane channel results in stability modes that are little changed in form or frequency from plane-channel Tollmien-Schlichting waves, and it thus follows from the transport-stability theory that eddy-promoter flows achieve the same heat transfer rates as turbulent flows while incurring significantly less dissipation.
Abstract: A classical transport enhancement problem is concerned with increasing the heat transfer in a system while minimizing penalties associated with shear stress, pressure drop, and viscous dissipation. It is shown by Reynolds' analogy that viscous dissipation in a wide class of flows scales linearly with the Nusselt number and quadratically with the Reynolds number. It thus follows that transport enhancement optimization is equivalent to a problem in hydrodynamic stability theory; a more unstable flow will achieve the same Nusselt number at a lower Reynolds number, and therefore at a fraction of the dissipative cost. This transport-stability theory is illustrated in a numerical study of supercritical (unsteady) two-dimensional flow in an eddy-promoter channel comprising a plane channel with an infinite periodic array of cylindrical obstructions.It is shown that the addition of small cylinders to a plane channel results in stability modes that are little changed in form or frequency from plane-channel Tollmien-Schlichting waves. However, eddy-promoter flows are dramatically less stable than their plane-channel counterparts owing to cylinder-induced shear-layer instability (with critical Reynolds numbers on the order of hundreds rather than thousands), and thus these flows yield heat transfer rates commensurate with those of a plane-channel turbulent flow but at much lower Reynolds number. Small-cylinder supercritical eddy-promoter flows are shown to roughly preserve the convective-diffusive Reynolds analogy, and it thus follows from the transport-stability theory that eddy-promoter flows achieve the same heat transfer rates as plane-channel turbulent flows while incurring significantly less dissipation.

129 citations


Journal ArticleDOI
TL;DR: In this article, the authors show that the rise in the upstream flow depth due to the effect of lateral inflow from the branch channel can be significant for rightangled, sharpedged junctions of rectangu...
Abstract: In combining open channel flow, the rise in the upstream flow depth due to the effect of lateral inflow from the branch channel can be significant. For rightangled, sharpedged junctions of rectangu...

121 citations


Book
01 Jan 1988
TL;DR: In this paper, the general equations of motion are derived from the general mass and force-momentum balances and extended to laminar flow along a flat surface, and a closed-form solution of the general equation of motion is given.
Abstract: Part 1 One-dimensional laminar flows: momentum transfer viscosity and shear stress Newtonian flow between parallel plates Newtonian flow in round tubes and circular annuli forced flow on non-Newtonian fluids through channels thin films and other open, gravitational flows Couette flows. Part 2 The general equations of motion: derivation of the general mass and force-momentum balances modified forms of the general mass and force-momentum balances exact, closed-form solutions of the equations of motion the Blasius solution for laminar flow along a flat surface integral boundary layer solution for laminar flow along a flat surface experimental results and extended solutions for laminar flow along a flat surface laminar flow over wedges and discs, circular cylinders and solid spheres the motion of bubbles and droplets generalized methods and other geometrics. Part 3 Flow relative to dispersed solids: flow through porous media the relative motion of fluids and dispersed solids.

Journal ArticleDOI
TL;DR: In this article, numerical solutions are presented for the problem of two-dimensional critical flow of an ideal fluid over a semi-circular obstacle attached to the bottom of a running stream.
Abstract: Numerical solutions are presented for the problem of two-dimensional “critical” flow of an ideal fluid over a semi-circular obstacle attached to the bottom of a running stream. The upstream Froude number and downstream flow speed are known in advance, and are therefore computed as part of the solution. The dependence of flow behaviour on obstacle size is discussed.

Journal ArticleDOI
TL;DR: In this article, high speed video movies indicate that the dominant flow structure is caused by the periodic ejection of intensely turbulent fluid with low streamwise momentum from the wall region into the relatively quiescent bulk fluid which it displaces and mixes with slowly.
Abstract: A turbulence structure in horizontal liquid streams bounded by a free surface and a wall has been investigated using 10–25 μm oxygen bubbles as tracers. High speed video movies indicate that the dominant flow structure is caused by the periodic ejection of intensely turbulent fluid with low streamwise momentum from the wall region into the relatively quiescent bulk fluid which it displaces and mixes with slowly. The motion of these bursts is constrained by the free interface. Between bursts and the interface a high speed region with a steep velocity gradient develops as a consequence. This in turn causes progress of the burst fluid toward the interface to slow down and eventually to turn back toward the wall, giving rise to characteristic rolling structures, which rotate clockwise if the flow is viewed as going from left to right. To complement the video studies, quantitative data were obtained by analyzing bubble streak lines generated by photography of optically chopped flashes. These data show that in the vicinity of the interface the velocity fluctuations normal to it are damped whereas those parallel to it are enhanced. Analysis of conditional samples of the data indicate that fluid with relatively low streamwise momentum tends to move toward the interface while fluid with high momentum moves away giving rise to rotating structures that roll along with the flow in agreement with the video studies. A high degree of correlation between ejection events near the wall and the fluid motion near the interface also confirm that the bursts extend across the flow stream. This has important implications for surface renewal theories of turbulent transport at fluid–fluid interfaces.

Journal ArticleDOI
TL;DR: In this paper, a theoretical and numerical investigation of streamwise-oriented Dean vortices in curved channel flow is presented, based on three-dimensional pseudospectral simulations of the incompressible time-dependent Navier-Stokes equations.
Abstract: A theoretical and numerical investigation of streamwise-oriented Dean vortices in curved channel flow is presented. The principal results are obtained from three-dimensional pseudospectral simulations of the incompressible time-dependent Navier-Stokes equations. With increasing Reynolds number, a sequence of transitions similar to that observed in non-turbulent Taylor-Couette flow is found. The transition from laminar curved channel Poiseuille flow to axisymmetric Dean vortex flow is studied using linear and weakly nonlinear analyses; these results are compared to the full simulations. Using the code, two transitions that cause the axisymmetric vortices to develop waves travelling in the streamwise direction at higher Reynolds numbers are discovered. The linear stability of axisymmetric Dean vortex flow to non-axisymmetric perturbations is examined. Associated with the two transitions are two different non-axisymmetric flows: undulating and twisting Dean vortex flow. Undulating vortices are similar to wavy Taylor vortices. Twisting vortices, with a much shorter streamwise wavelength, are dissimilar; to our knowledge, they have no counterpart in the Taylor-Couette problem. At sufficiently high Reynolds numbers, linear growth rates associated with twisting vortices far exceed those associated with undulating vortices. For the channel curvatures studied, angular speeds of both kinds of travelling waves are only weakly dependent on Reynolds number and wavenumber. A bifurcation limits the vortex spacings that can be examined and suggests an Eckhaus stability boundary. The development of wavy vortex flows from small-amplitude disturbances shows that full development of undulating vortices may require a streamwise distance greater than one circumference, whereas for sufficiently large Reynolds numbers, twisting vortices reach equilibrium amplitude within half this distance and are therefore more likely to be observed experimentally. We suggest twisting vortices are due to a shear instability.

Journal ArticleDOI
TL;DR: In this article, a uniform mean-gradient shear flow was produced using a ten-layer closed-loop water channel, providing long enough dimensionless flow development times (τ = (x/Ū) (∂ Ū/∂z)) for the turbulence to grow.
Abstract: A uniform-mean-gradient shear flow was produced using a ten-layer closed-loop water channel, providing long enough dimensionless flow development times (τ = (x/Ū) (∂ Ū/∂z)) for the turbulence to grow. The rate of growth of the turbulence compares well with similar measurements in wind-tunnel-generated uniform shear flows for which the mean shears and centreline velocities are larger by an order of magnitude. Preliminary investigations were undertaken to study the growth of the turbulent intensity as functions of the mean shear, centreline velocity, and initial disturbance lengthscales. Initial disturbance lengthscales were varied by using grids of different mesh sizes.Turbulent intensities were found to increase nearly linearly with τ. Differences in grid mesh size produce different offsets in the turbulent intensity level, with a larger grid mesh producing a higher positive offset. This offset persists throughout the growth of the turbulent intensity. These observations provide valuable insight in interpreting previous wind-tunnel measurements, in particular the high-shear experiments of Karnik & Tavoularis (1983). Comparison with the theoretical predictions of Tavoularis (1985) allows for an improved universal characterization of evolving turbulence in a uniform mean shear.

Journal ArticleDOI
TL;DR: An integrated approach to the design of automatic control systems for canals using Linear Quadratic Regulator theory is developed in this article, where the one-dimensional partial differential equations describing open channel flow (Saint-Venant equations) are linearized about equilibrium flow conditions and discretized spatially to provide a set of approximate ordinary differential equations (ODE) which describe the effects of gate openings on depth and flow rate.
Abstract: An integrated approach to the design of automatic control systems for canals using Linear Quadratic Regulator theory is developed. The one‐dimensional partial differential equations (PDE) describing open channel flow (Saint‐Venant equations) are linearized about equilibrium flow conditions and discretized spatially to provide a set of approximate ordinary differential equations (ODE) which describe the effects of gate openings on depth and flow rate. Standard linear quadratic techniques are used to design a regulator. The requirement to measure all states is obviated by the construction of an observer using only measurements of depth adjacent to control gates. Simulation results are presented which show dramatic improvements in transient response over the uncontrolled case. Use of these techniques in water conveyance canals facilitates more rapid changes in discharge, and by permitting longer periods of off‐peak pumping could greatly reduce pumping costs.

Journal ArticleDOI
TL;DR: In this paper, the naphthalene sublimation technique was used to investigate the heat transfer characteristics of turbulent air flow in a two-pass channel and a test section that resembles the internal cooling passages of gas turbine airfoils was employed.
Abstract: The naphthalene sublimation technique is used to investigate the heat transfer characteristics of turbulent air flow in a two-pass channel. A test section that resembles the internal cooling passages of gas turbine airfoils is employed. The local Sherwood numbers on the ribbed walls were found to be 1.5-6.5 times those for a fully developed flow in a smooth square duct. Depending on the rib angle-of-attack and the Reynolds number, the average ribbed-wall Sherwood numbers were 2.5-3.5 times higher than the fully developed values.

Journal ArticleDOI
TL;DR: In this paper, the exact solutions of the Navier-Stokes equations governing the steady two-dimensional motions of an incompressible viscous fluid from a line source at the intersection of two rigid plane walls are examined.
Abstract: We examine various perturbations of Jeffery-Hamel flows, the exact solutions of the Navier-Stokes equations governing the steady two-dimensional motions of an incompressible viscous fluid from a line source at the intersection of two rigid plane walls. First a pitchfork bifurcation of the Jeffery-Hamel flows themselves is described by perturbation theory. This description is then used as a basis to investigate the spatial development of arbitrary small steady two-dimensional perturbations of a Jeffery-Hamel flow; both linear and weakly nonlinear perturbations are treated for plane and nearly plane walls. It is found that there is strong interaction of the disturbances up- and downstream if the angle between the planes exceeds a critical value 2α2, which depends on the value of the Reynolds number. Finally, the problem of linear temporal stability of Jeffery-Hamel flows is broached and again the importance of specifying conditions up- and downstream is revealed. All these results are used to interpret the development of flow along a channel with walls of small curvature. Fraenkel's (1962) approximation of channel flow locally by Jeffery-Hamel flows is supported with the added proviso that the angle between the two walls at each station is less than 2α2.

Journal ArticleDOI
TL;DR: In this paper, a method for the prediction of fully developed, turbulent, stratified, two-phase flow in horizontal and inclined pipes and channels is presented, which solves the two-dimensional momentum equations for both phases and accounts for the effects of turbulence through the use of the k-ϵ two-equation model of turbulence.

Journal ArticleDOI
TL;DR: In this paper, it is shown that a viscous fluid flow with curved streamlines can support both Tollmien-Schlichting and Taylor-Gortler instabilities.
Abstract: It is known that a viscous fluid flow with curved streamlines can support both Tollmien-Schlichting and Taylor-Gortler instabilities. The question of which linear mode is dominant at finite values of the Reynolds numbers was discussed by Gibson & Cooke ( Q. Jl Mech. appl. Math . 27, 149 (1974)). In a situation where both modes are possible on the basis of linear theory a nonlinear theory must be used, however, to determine the effect of the interaction of the instabilities. The details of this interaction are of practical importance because of its possible catastrophic effects on mechanisms used for laminar flow control. Here this interaction is studied in the context of fully developed flows in curved channels. Apart from technical differences associated with boundary-layer growth the structures of the instabilities in this flow can be very similar to those in the practically more important external boundary-layer situation. The interaction is shown to have two distinct phases depending on the size of the input disturbances. At very low amplitudes two oblique Tollmien–Schlichting waves interact with a Gortler vortex in such a manner that the scaled amplitudes become infinite at a finite time. This type of interaction is described by ordinary differential amplitude equations with quadratic nonlinearities. A stronger type of interaction occurs at larger input disturbance amplitudes and leads to a more complicated type of evolution equation. The solution of these equations now depends critically on the orientation of the wavefronts of the Tollmien–Schlichting waves to the Gortler vortex. Thus, if the angle between the directions of the vortex and the waves is greater than 41.6° this stronger interaction again terminates in a singularity at a finite time; otherwise the breakdown is exponential, taking an infinite time. Moreover, the stronger interaction can take place in the absence of curvature, in which case the longitudinal vortex is entirely driven by the Tollmien–Schlichting waves.

Journal ArticleDOI
TL;DR: In this article, a theoretical model for division of flow in a short branch channel set at right angles to a main channel is presented for various width ratios of the branch channel to the main channel.
Abstract: A theoretical model for division of flow in a short branch channel set at right angles to a main channel is presented for various width ratios of the branch channel to the main channel. The model is developed using the principles of momentum, energy, and continuity and is based on the existence of free flow conditions in the branch channel. The analysis makes use of the similarity of flow configuration between the division of flow in a branch channel and in a two-dimensional lateral conduit outlet fitted with a barrier. This similarity of flow is used to estimate the contraction coefficient of the converging jet entering the branch channel. The ratio of the branch channel flow to the main channel flow is related to the Froude number in the main channel section downstream of the junction. Data from present experimental studies and those from earlier investigations are presented to validate the theoretical model.

01 Jan 1988
TL;DR: In this paper, an experimental description of the flow structure of non-Newtonian slurries in the laminar, transitional, and full turbulent pipe flow regimes is presented.
Abstract: An experimental description of the flow structure of non-Newtonian slurries in the laminar, transitional, and full turbulent pipe flow regimes is the primary objective of this research. Experiments were conducted in a large-scale pipe slurry flow facility with an inside pipe diameter of 51 mm. The transparent slurry formulated for these experiments exhibited a yield-power-law behavior from cup viscometer measurements. The velocity profile for laminar flow from laser Doppler velocimeter (LDV) measurements had a central plug flow region, and it was in agreement with theory. The range of the transition region was narrower than that for a Newtonian fluid. The mean velocity profile for turbulent flow was close to a 1/7 power-law velocity profile. The rms longitudinal velocity profile was also similar to a classical turbulent pipe flow experiment for a Newtonian fluid; however, the rms tangential velocity profile was significantly different. 11 refs., 9 figs., 1 tab.

Journal ArticleDOI
TL;DR: In this article, a simple weir-type flow analysis is found adequate to describe the plunging flow regime and a surface stream analysis is performed to predict the characteristics of the streaming flow.
Abstract: This note presents the results of an experimental study on the hydraulics of pool and weir fishways. A simple weir-type flow analysis is found adequate to describe the plunging flow regime. A surface stream analysis is performed to predict the characteristics of the streaming flow. A parameter is developed to predict the transition from plunging to streaming flow.

Proceedings ArticleDOI
01 Jan 1988
TL;DR: In this paper, the mean flow and turbulence quantities around a multielement airfoil model have been made using pressure and hot-wire probes, and the results obtained in two test cases at the chord Reynolds number of 3 million and the freestream Mach number of 0.2 show a number of features of the complex flows that are important in accurate modeling of these flows by numerical methods.
Abstract: Detailed measurements of mean-flow and turbulence quantities around a multielement airfoil model have been made using pressure and hot-wire probes. The results obtained in two test cases at the chord Reynolds number of 3 million and the freestream Mach number of 0.2 show a number of features of the complex flows that are important in accurate modeling of these flows by numerical methods. Many parts of the shear flow vastly deviate from classical flows, and the interaction with the external potential flow is very strong.


Patent
16 Dec 1988
TL;DR: In this paper, a manifold system is constructed for evenly distributing a liquid to and/or evenly collecting a liquid from, a cell of a separator system, such that the flow paths between the manifold inlet(s) and manifold outlet (s) are all approximately hydraulically identical in numbers, types, and dimensions of flow components.
Abstract: A manifold system is constructed for evenly distributing a liquid to, and/or evenly collecting a liquid from, a cell of a separator system. The flow paths between the manifold inlet(s) and manifold outlet(s) are all approximately hydraulically identical in numbers, types, and dimensions of flow components, such that: (a) the flow rates to/from each of multiple inlets/outlets is equivalent, even with changes in overall pressure drop or flow rate, and (b) the time required for liquid to traverse each of the manifold flow paths is approximately identical, enabling plug flow through the cell.

Journal ArticleDOI
TL;DR: In this article, a detailed set of experiments were performed enabling the effects of flow split, inlet quality and inlet mass flux on the phase separation and pressure characteristics to be determined.

Journal ArticleDOI
TL;DR: In this article, the authors present the results of an experimental study on the hydraulics of culverts with offset baffles to pass fish using analytical considerations and experimental observations, a flow equation has been developed between the discharge, diameter, depth, and slope for a culvert fish way with the standard offset baffle system.
Abstract: This paper presents the results of an experimental study on the hydraulics of culverts with offset baffles to pass fish Using analytical considerations and experimental observations, a flow equation has been developed between the discharge, diameter, depth, and slope for a culvert fish way with the standard offset baffle system The velocity field at the slot has also been evaluated Some further experiments were performed to assess the effect of baffle spacing and height on the hydraulics of the culvert fishway Key words: culverts, fishways, baffles, hydraulics, open-channel flow, turbulent flow

Journal ArticleDOI
TL;DR: In this article, the authors extended the biharmonic boundary integral solution of two-dimensional creeping flow of an incompressible Newtonian fluid to problems with free surfaces, and demonstrated this by solving the Bretherton problem of a 2D air bubble traveling in a channel.